Machine for abrading, polishing and cleaning



June 27, 1967 w. F. SMITH ETAL 3,327,43 MACHINE FOR ABRADING, POLISHING AND CLEANING Filed Sept. 25, 1964 2 mo ,6 way United States. Patent 3,327,431 MACHINE FOR ABRADING, POLISHING AND CLEANING William F. Smith, 160 Oak Drive, and Elmo R. Mays, 325 Pine, both of Lake Jackson, Tex. 77566 Filed Sept. 23, 1964, Ser. No. 398,499 5 Claims. (Cl. 51-163) This invention comprises a novel and useful machine for abrading, polishing and cleaning and more particularly relates to an apparatus for the rapid abrading, polishing and cleaning of surfaces of objects especially by lapidaries and hobbyists.

Lapidaries, both professional and those pursuing the art as a hobby, employ predominantly one major technique for the abrading and polishing of baroque and preformed stones. This technique is referred to as tumbling. The action obtained with a tumbler involves a revolving tumbler mechanism and a container for the stones, called a barrel, which barrel, depending upon its diameter, must turn at a certain speed. The barrel may be one of two major designs: (1) a barrel as a separate component which is placed upon the revolving tumbler mechanism, such as rollers, and (2) an aflixed barrel, i.e., semipermanently attached to the tumbler mechanism. The separate barrels are generally round and are placed onto the tumbler mechanism in a horizontal position whereas the attached barrel may be round or geometrically shaped and mounted at an angle, e.g., 45 degrees. In either case, the abrading and polishing action is the same with the exception that the geometric shaped barrels, e.g., hexagon shaped require about 40% longer running time to abrade and polish. In general, the procedure with a tumbler involves three grinding runs and a polish run. The first grinding or abrading of the stones is generally conducted with a number 80 silicon carbide grit and water. Hereinafter, when the term grit appears herein, it means silicon carbide of the mesh or size indicated by the number. The load is placed upon the tumbler and grinding is commenced. The grinding time varies from three days to three weeks but on the average requires about five days. This time depends upon the hardness of the stones, for example agate requires five to eight days, but a more critical factor is the revolutions per minute (r.p.m.) of the barrel and the consistency of the water-grit mix. The water-grit mix is referred to in the art as goop. The second and third grindings employ finer grits (e.g., number 400 and number 600 grits respectively) with like running times and the final polish run employs the same amount of time with a polish such as tin oxide rather than grit. The total time involved for abrading and polishing of stones, from rough to finish, is thus on the order of twenty days provided that the conditions, such as speed of the barrel and goop consistency, are correct.

This operation thus has the disadvantage of being noisy, extremely time consuming, and highly critical in the conditions necessary to abrade and polish. In particular, the critical conditions necessary affect the layman, beginner and those persons desiring to abrade and polish only a small portion of stone as for example a pound or less. Further, due to the rolling action which causes a hanging together of the objects in the barrel, certain stones and objects cannot be abraded, polished or cleaned without even more critical requirements (e.g., obsidian and colored glasses) and some materials such as sea shells, dental plates, jewelry and seeds cannot be tumbled at all.

In order to avoid these problems and disadvantages, a more recent innovation is to employ a grinding table which, rather than rolling or tumbling the objects, vi-

brates them. One such table is the subject of US. Patent 2,949,908 which provides an improvement over the tumbling method in the grinding of objects such as slabs of stone, stone book ends, paper weights, and the like, but its performance in the area of baroque and preformed stones is lacking. The disadvantages are inherent in that the grit settles with the larger, heavier stones with the result being more abrasive action on the heavier stones and fiats occur. By the term flats it is meant that one spot on the stones abrades more that the rest of the stone. Conversely, the topmost stones receive the least abrasive action. In the case of sea shells, dental plates, jewelry findings and seeds, this occurrence of greater abraded flat areas is detrimental. In all cases, of baroque and preformed stones, an excellent polish is hard to obtain. For example, in the case of agate, the agate is vibrated fairly rapidly, since it is hard and can take the banging together in an attempt to avoid flats and after the three grit runs by vibration, the agate is removed and polished in a tumbler.

It is an object of the present invention to provide an apparatus for abrading, polishing and cleaning which apparatus is of particular value to the lapidarists and hobbyists due to its simple, quite and noncritical operation.

It is further an object of the invention to provide an apparatus which can be used for abrading, polishing and cleaning of natural and synthetic stones, colored glasses, sea shells, jewelry and dental plates.

A further object of the invention is to provide an apparatus which, though of such design and action that even the hardest of stones can be abraded and polished, can also be used for the scarification of seeds.

A further object of this invention is to provide such an apparatus for abrading, polishing and cleaning of objects which apparatus uses comparatively small amounts of grit and water. Thus there is a saving involved upon operation and no critical composition of goop has to be maintained.

A further object of this invention is to provide such an apparatus which in working stones is faster cutting and faster polishing.

A further object is to provide such an apparatus for abrading and polishing which apparatus produces polished stones and glasses directly and simply employing only grit or polish with water as desired.

And a still further object is to provide an apparatus wherewith those people not trained in the art of lapping and polishing can produce polished stones and glasses easily and rapidly without concern for critical mechanical factors and critical grinding and polishing mixes.

These objects together with other objects and advantages will become apparent in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout and in which:

FIGURE 1 is a side view of one suitable form of apparatus in accordance with the principles of this invention; and,

FIGURE 2 is a side view of an alternate suitable form of apparatus in accordance with the principles of this invention; and,

FIGURE 3 is a view of the rotor of the motor shown in FIGURES 1 and 2.

It has been discovered that when an electric motor is provided with an off-centered weight attached to its rotor, and that when one end of the motor, preferably the end opposite the weighted end is resiliently attached to a fixed point, the motor, while running, performs an unusual motion. It has further been discovered that when 3 a container is attached to the motor, objects placed in the container will assume a triple motion, i.e., end to end turning, side to side turning, and a definite well defined repeating circular pattern movement from top to bottom of the container, if the container makes an angle of greater than degrees and less than 50 degrees and preferably of from about to 30 degrees with the horizontal. It has still further been discovered that if the motor is resiliently secured with an adjustable securing means, as for example a nut and bolt, the speed of the movements can be regulated by the tightness of the nut. For example, when the nut is loose, the repeating circular motion from bottom to top of the container by the objects therein stops, the end to end motion is practically nonexistant and only a slow side to side motion exists. As the nut is tightened, all three motions begin with the movement from bottom to top being the last to commence. In order for the apparatus to perform as desired and taught, all three actions must occur simultaneously.

Referring to FIGURE 1, wherein the particular arrangement may be more fully understood, the apparatus illustrated consists of an angled supporting member 10, which supporting member is attached to an electric motor 11 by means of an adjusting nut and bolt 12 and a resilient gasket 13. The electric motor 11 is provided with an ofi-center weight 19 attached to the rotor 18 by means of rotor shaft which weight provides the unusual motion to said motor due to the fixed point mounting of the motor 11 by the adjusting nut and bolt 12. This motion is transferred by means of bracket 14 to container 15 which container holds the objects to be abraded, polished or cleaned. It is specifically pointed out that supporting member 10 is angled and this will always be the case when bracket 14 is straight in order to maintain angle alpha in the range of from greater than 10 degrees to less than 50 degrees and preferably at 15 to 30 degrees.

Referring to FIGURE 2, wherein an alternate method of mounting and obtaining the angle alpha is shown, the apparatus illustrated consists of a straight supporting member 16, which supporting member is attached to an electric motor 11 by means of an adjusting nut and bolt 12 and a resilient gasket 13. The electric motor 11 is provided with an off-center weight attached to the rotor which weight causes the unusual motion to said motor due to the fixed point mounting of the motor by the adjusting nut and bolt 12. This motion is transferred by means of angled bracket 17 to container 15 which container holds the objects to be abraded, polished or cleaned. It is especially and specifically pointed out that bracket member 17 is angled and this will always be the case when the supporting member 16 is straight in order to maintain angle alpha in the desired range. It is obvious to those skilled in mechanics that both the supporting member and the bracket could be angled in such a way that the angle alpha would be in the desired range.

The container may be cylindrical or rectangular in shape and of any suitable material such as plastic, glass reinforced plastics and the like, however, the composition of the container is not critical since the motion of the objects is so unique that a glass container may be used for abrading the hardest stones without breaking. It is not essential that the container have a lid. Due to the angle of the container and the action of the objects therein the objects remain in the container. Further, with the lid 011, the particular action and motion of the objects Within the container is readily observable.

No special requirements are placed on the motor other than the motor be provided with an off-centered weight fastened to the rotor of the motor. Thus if a motor of greater horsepower be used, then a larger container can be used in order to increase the number of objects to be subjected to the action of the unit.

The angle the container makes with the horizontal is 4 highly critical if the objects in the container are to be subjected to the aforementioned and described triple motion. This angle, which is represented by the angle alpha in the drawings, must be greater than 10 degrees and less than 50 degrees and preferably 15 to 30 degrees. If the containeris at zero degrees with the horizontal, the third motion, that of moving from topto bottom of the container continuously is lost and the action becomes then simply a vibration very similar to that of a vibrating table. If the angle alpha is increased beyond 50 degrees,

the objects collect at the bottom, stack up and little action of any kind is obtained.

In order to further illustrate thepractice and operation of the present invention, the following examples are presented. However, these examples are for purposes of illustration and are not to be construed as limiting the invention thereto.

Example 1.Run made with obsidian An abrading and polishing unit was rigged by employing an electric motor having an otf-center weight on the rotor and a polyethylene container of approximately 6 /2 inches inlength and 2% inches in diameter. The electric motor was made by Daton Electrical Manufacturing Company and had the following specifications:

(a) 115 volts, 60 cycles (b) 1720 revolutions per minute (c) horsepower spoon of number 811 grit and two level tablespoons of I water. The motor was started and the action of the stones were watched over a 45 minute period while various different angles of the mounting bracket were tried by bending the mounting bracket. By thus bending the mounting bracket, various angles of the container were observed. Finally, -a motor angle of about 25 degrees was employed for the run. The motor was allowed to run for a total time of 18 hours 10 minutes, the stones were re-. moved, washed and dried in an oven and weighed. A weight of 311.7 was obtained representing a weight loss of 42.4 grams or about 12%.

The 311.7 grams of obsidian were returned to the abrader-polisher. It is pointed out here that in this example and all others, any time a grit change was made, the bottle was thoroughly cleaned and for polish runs, a separate container was employed. To this was added one tablespoon of number 400 grit and two tablespoons of water. The motor was allowed to run for 9 hours 50 minutes total time and the stones were removed, washed, dried and weighed. A weight of 287.4 grams was obtained representing a weight loss of 24.3 grams or 8%.

The 287.4 grams of obsidian were returned to the container of the unit along with 1 tablespoon of number 600 grit and three tablespoons of water. The motor was allowed to run for 19 hours 15 minutes and the stones were removed, washed, dried and weighed. A weight of 265.8 grams was obtained representing a weight loss of 18.9 grams or 6%. Total percent weight loss for the three grind runs was 26%.

The 268.5 grams of obsidian were loaded into a plastic container like the one above described which plastic container Was employed for polish runs only. This is to assure that no grit gets into the polish goop. Along with the obsidian were placed 1 level tablespoon of tin oxide powder and four tablespoons of water. The motor was run for 47 hours 5 minutes and the obsidian was polished. Total over-all running time was hours and 5 minutes.-

Example 2.--Run made with glass The apparatus of Example 1 was employed with the following:

485.7 grams of blue and green, fresh broken glass of assorted sizes.

2 tablespoons of number 80 grit 2 tablespoons of water The total run time on this 80 grit was 36 hours 50 minutes. Only about one-half of the grit was used up. One tablespoon of grit is suflicient. There was a 9% weight loss. This run with number 80 grit was for 3-6 hours because the action of the abrader-polisher is such that the number 400 grit is not necessary and can be left out if desired. The glass was loaded into the container along with one tablespoon of number 600 grit and two tablespoons of water. The motor was turned on for 20 hours 15 minutes and at the end of this time, the glass was not polished due to the loss of the resilient gasket which caused a loss in the motion produced by the abraderpolisher. The resilient washed is thus necessary and essential in order to obtain the desired action.

The gasket was replaced and the motor turned on for 21 hours 55 minutes. At the end of this time the glass was removed from the container, washed and loaded into the polish container along with /2 tablespoon of tin oxide and two tablespoons of water. An excellent polish Was obtained in 36 hours 20 minutes. The total overall run time was 94 hours 5 minutes.

Example 3.Run made with seeds Scarification of seeds is important to many people, e.g., nurserymen, conservation personnel of the government, etc. since some seeds are so heavily coated, it takes years for the coating to erode away in order for the seeds to germinate. For example, mesquite beans may take years or more. The Pacific Silver Fir is another which requires a long time for the seeds to germinate naturally due to the seed coatings.

The abrader-polisher as set forth in Example 1 Was loaded with seeds from the Pacific Silver Fir. The seeds covered the bottom of the container to a depth of /2 inch. An equal volume of fresh sand blasting sand was placed into the container with the seeds and the motor was started and run for four hours. At the end of this time, the husk had been removed along with the hard rosin-like coating and the sand was starting to abrade the hard outer shell of the seed itself.

Example 4.Ran with sea shells The cleaning and polishing of sea shells is important to shell collectors in that the shells as obtained are generally covered with a white coating and sometimes with other marine growths.

The apparatus of Example 1 was employed with the container at 20 degrees with the horizontal. The con tainer was loaded with 203.5 grams of assorted sea shells varying in size from small clam shells of about 4 inch in width to the type known as angel wings which were 1% inches long by inch wide. Along with the sea shells, were placed 3 tablespoons of fresh sand blasters sand and 3 tablespoons of water. The motor was turned on and after 20 hours 5 minutes, the shells were cleaned and the angel wings were not broken.

Example 5.Rzm with mixed stones The apparatus of Example 1 was employed with a mixture of stones consisting of agate, opalized petrified wood and petrified wood. The container of the apparatus was loaded as follows:

470.7 grams of stones 1 tablespoon of 80 grit 2 tablespoons of water y 6 The motor was started and allowed to run .for 24 hours and there was a weight loss of 4%.

The stones were then loaded back into the container and additional stones were added until the weight came to 570 grams. This was done with stones which had previously been run with number grit and was done here to purposely load the container to a height well past of its total height. Conventional rolling tumblers cannot be loaded near this full and still continue to abrade the stones therein. Along with the stones were placed 1 tablespoon of number 400 grit and two tablespoons of water. The motor was run for 24 hours and there was a weight loss of 3.9%.

The 487.4 grams left from the 400 grit run was loaded into the container along with 1 tablespoon of number 600 grit and 2 tablespoons of water. The motor was run for 24 hours and there was a 3.4% weight loss. The stones Were then loaded into a container for polish along with 1 tablespoon of tin oxide and 3 tablespoons of water. The motor was run for 24 hours and an excellent polish was obtained upon the stones. This was a total time of 96 hours.

Other examples as well as runs made on a conventional rolling tumbler are listed in the following table. The tumbler was powered by a Dayton volt, 60 cycle, 1520 r.p.m. and horsepower motor with a separate round metal can. It is found that best results were obtained when a one gallon can was employed which was loaded to at least /2 full, i.e., about 5 pounds of stones, requiring 1 pound of grit with water to about /2 inch over the top of the stones. The speed was in the range of 30 to 35 r.p.m.

A one quart can was loaded to /2 full with stones and tried with a number 80 grit for 119 hours 5 minutes and abandoned due to very little cutting and abraiding of the stones.

The time of running in all cases for the one gallon can Was until the stones had obtained an acceptable abrading in the grit specified and in the polish until an excellent polish for commercial selling was obtained. In all cases the stones were checked periodically by stopping for a short period of time, removing at least three stones at random, washing and examining. These were then returned to the can and the run was continued.

Example Time Time Time Time Time Number 80 grit, 400 grit, 600 grit, polish, total,

l1r./nn'n. hr./min. biz/min. h1./mi!1. hr./min.

455/00 skipped 48/00 23/30 113/30 48/00 48/00 Skipped 23/30 113/30 Ex. 6 zlhisblrun was made with petrified wood in a commercial um er.

Ex. 7 This run was made with agate in a commercial tumbler. It was necessary to make a long 400 grit run since the 80 grit run was short.

Ex. 8 This run was made with opalized wood in a commerial tumbbler. Stones were not polished. Some of these stones were later polished in the abrader-polisher oi the present invention.

Ex. 9 and 10 These two runs were made with pint of mixed stones in the abrader-polisher of the present invention.

Example 11 An abrading and polishing unit was rigged and employed as taught in Example 1 with the exception that the motor was mounted level and the container was mounted such that the angle alpha was 22 degrees by angling the container bracket. The container was loaded with 329.0 grams of opalized wood, 1 tablespoon of number 80 grit and 1 tablespoon of water. The adjusting nut was set to give a gentle action due to the delicate nature of these stones. The motor Was started and after 23 hours, a 4.6% weight loss was obtained. The stones were then run through a number 400 grit, a number 600 grit and polished with a tin oxide run.

Besides the grits and sand mentioned herein, other abrading and polishing compounds can be employed, e.g., broken grinding wheels, beach sand, tripoli powder, cerium oxide, chrome oxide and the like.

We claim:

1. An apparatus for abrading, polishing and cleaning objects which comprises a mounting bracket, a motor having vibrating means attached thereto at one end, said motor being resiliently attached to said mounting bracket at the other end for movement and, a container rigidly attached to the side of the motor between said ends so as to form an angle of from 10 to 50 degrees 'between said container and a horizontal plane whereby said motor and container are moved with a compound motion about said resilient mounting relative to said bracket.

2. The apparatus of claim 1 wherein the angle is from 15 to 30' degrees.

3. An apparatus for abrading, polishing and cleaning objects which comprises a mounting bracket, a motor having an ofi-center weight attached to the rotor thereof at one end, said motor being resiliently and adj-ustably attached to said mounting bracket at the other end for movement and, a container rigidly attached to the nonrotary portion of said motor between said ends so as to form an angle of from 10 to 50 degrees between said container and a horizontal plane whereby said motor and container are moved with a compound motion about said resilient mounting relative to said bracket.

4. The apparatus of claim 3 wherein the angle is from 15 to 30 degrees.

5. The apparatus of claim 3 wherein the said container is cylindrical.

References Cited UNITED STATES PATENTS 1,751,087 3/ 1930 Jackson. 2,284,671 6/ 1942 Meinzer 517 2,728,562 12/ 1955 Bailey. 2,967,434 1/1961 Mahfeldt 57--7 3,093,940 6/1966 Balz 51163 FOREIGN PATENTS 483,359 4/ 1938 Great Britain.

HAROLD D. WHITEHEAD, Primary Examiner. 

1. AN APPARATUS FOR ABRADING, POLISHING AND CLEANING OBJECTS WHICH COMPRISES A MOUNTING BRACKET, A MOTOR HAVING VIBRATING MEANS ATTACHED THERETO AT ONE END, SAID MOTOR BEING RESILIENTLY ATTACHED TO SAID MOUNTING BRACKET AT THE OTHER END FOR MOVEMENT AND, A CONTAINER RIGIDLY ATTACHED TO THE SIDE OF THE MOTOR BETWEEN SAID ENDS SO AS TO FORM AN ANGLE OF FROM 10 TO 50 DEGREES BETWEEN SAID CONTAINER AND A HORIZONTAL PLANE WHEREBY SAID MOTOR AND CONTAINER ARE MOVED WITH A COMPOUND MOTION ABOUT SAID RESILIENT MOUNTING RELATIVE TO SAID BRACKET. 